Compositions of matter of improved appearance in daylight, containing a 3.5-diaminopyrazine-2.6-dicarboxylic acid derivative



United States Patent The invention concerns a process for theimprovement of the appearance in daylight of more or less colorless orwhite carriers by incorporation therein of slight amounts of the3.5-bis-(sec. amino)-pyrazine-2.6-di-.

carboxylic acid amides obtained according to the new production processwhich, in UV-containing light, fluoresce violet-blue, blue to greenblue.

Up to now only a few processes are known for the production of 3.2;5.6-bis- (2.4-dioxo-1.2.3.4'-tetrahydro)-l.4-pyrimidino]-pyrazineswhich have been given the common name of bis-alloxazines. According tothe literature these processes only give poor yields because of the sidereactions which occur and because of the often troublesome purificationof the crude products due to these side reactions. Thus for example,Bredereck et al. (Berichte der deutschen chemischen Gesellschaft, vol.86, page 845 (1953) disclose yields of at most 45% of the theoreticalfor the condensation of 2 molecules of 1.3-dimethyl-4,5-diamino-uracilin mineral acid solution while splitting off ammonium salt, or in vol.87 page 1268 (1954) give the same yields for the condensation of onemolecule of 1.3-dimethyl-4.5- diamino-uracil with one molecule of1.3-dimethyl-al1oxan. Also Timmis in US. Patent No. 2,581,889 mentionsyields of up to 63% of crude 3.2;5.6-bis-[(1.3'-dimethyl- 2'.4' dioxo1.2.3.4 tetrahydro) 1.4 pyrimidino1- pyrazine (also called1.3.1.3'-tetramethyl-bis-alloxazine) for the condensation of onemolecule of 1.3-dimethy1- 4-amino-5-nitroso-uracil with one mol of1.3-dimethyl barbituric acid.

It has now been found that very good yields of 3.5- diamino-pyrazine 2.6dicarboxylic acid derivatives are obtained if one mol of1.3-disubstituted 4-amino-uracil is condensed with 1 mol of1.3-disubstituted 4-amino-5- nitroso-uracil while splitting off one molof water and one mol of ammonia to form the corresponding 3.2;5.6- bis[(2 .4' dioxo l.2.3.4' tetrahydro) l'.4' pyrimidino1-pyrazine and thiscompound is saponified by known methods either direct or in steps toform derivatives of 3.5-diaminopyrazine-2.6-dicarboxylic acid, ifdesired while modifying free carboxylic groups by ami' dation.

The good yields obtained in the said process are chiefly due to the factthat the new condensation of 1.3- disubstituted 4-amino-uracils with1.3-disubstituted 4-amino-S-nitroso-uracils to form3.2;5.6-bis-[(2.4'-dioxo- 1.2'.3'.4' tetrahydro) 1.4' pyrimidine]pyrazines, which is performed advantageously in polar organic solventswith an acid reaction and preferably in lower fatty acids, in particularin glacial acetic acid, proceeds more uniformly than the knownprocesses.

Good yields of up to 90% of the theoretical of these valuableintermediate products are obtained and this in contrast to the synthesesmentioned even when the nitrogen atoms of the uracils are substituted byhigher organic radicals than methyl groups. Also the 3.2;5.6-bis-3,175,9 0 Patented Mar. 39, 1965 ice dinol-pyrazines variouslysubstituted at the nitrogen atoms of the two tetrahydropyrimidine ringsare obtainable in good yields according. to the new process. That thestarting materials used according to the said process would condense sofavorably was surprising in view of atom. As nitrogen substituents bothhydrocarbon radicals and'also substituted hydrocarbon radicals of thealiphatic, araliphatic, alicyclic, or aromatic series are used, forexample, methyl, ethyl, n propyl, isopropyl, n-butyl, hydroxyethyl,methoxyethyl, ethoxyethyl, -methoxypropyl, benzyl, chlorobenzyl,methylbenzyl, cyclohexyl, methyl-cyclohexyl, phenyl, methylphenyl,chlorophenyl, methoxyphenyl groups and starting materials having thesame or different substituents at the nitrogen atom can be condensed.

Saponification of3.2;5.6-bis-[(2'.4-dioXo-1.2.3.4-tetrahydro)-l'.4-pyrimidino]-pyrazinesin aqueous, alcoholic or organic/aqueous solution or suspension, withalkalies such as sodium or potassium hydroxide, leads to thecorresponding 3.5-bis-(sec. amino)-pyrazine-2.6-dicarboxylic acidamides. Under more vigorous conditions, for example in ethanolicpotassium hydroxide, the 3.5-bis-(sec. amino)-pyrazine-2.6-dicarboxylicacid monoamides are formed. In these compounds the free carboxyl groupcan be converted with thionyl chloride into the carboxylic acid halidegroup. Aminolysis of this group leads to the acid amides. A technicallyparticularly simple method of performing the amidation consists indissolving the carboxylic acid and the amine to be introduced in astrong tertiary nitrogen base such as pyridine, homologous pyridines ortriethylamines and then stirring in gradually the necessary amount ofthionyl chloride or phosphorus trichloride or bromide in the cold. Afterremoval of the nitrogen base by dilution with water or steam, the3.5-diaminopyrazine-2.6-dicarboxylic acid diamide is obtained direct.The free carbonyl group, which may be in the form of its salts, can alsobe esterified, for example on treating with dialkyl sulphates.

Other derivatives can be obtained in the aminolysis of the acid chloridegroup by using amines which contain different substituents from thoseoriginally at the nitrogen atom which was linked to the carbonyl group.In this way, in particular also aromatic and heterocyclic amine radicalscan be introduced, for example phenylamino, methylphenylamino,chlorophenylamino, methoxpyhenylamino, pyridyl-(2)-amino and morpholinogroups. However, it is also possible to introduce hydroxy-alkylaminogroups in this way, for example the monoethanolamide, diethanolamide,2-hydroxypropylamide group, also aminoalkyl carboxyl acid, carboxylicacid ester and carboxylic acid amide groups. Even urea and substitutedurea groups, e.g. the monophenyl urea group can be introduced in thisway.

However, also unsymmetrical amidated end products can be obtained byaminolysis of 3.2;5. 6-bis-[(2'.4-dioxo 1'.2'.3'.4 tetrahydro)pyrimidino 1'.4] pyrazines at a higher temperature with amines such ase.g. benzylamine, whereby only one dioxo-tetrahydro-pyrimidino ring issplit, and then further hydrolysing with alkalies.

4 There are, thus, several methods by which it is possible to vary atwill the substitution of a diaminopyrazine dicarboxylic acid amidesaccording to the desired intended use. H 5

' 0.9 The. following sequence illustrates the reactions described:

radical, in particular the radical of a primary amine are particularlyvaluable because of their violet-blue, blue to green-blue fluorescence.In the above sequence of reactions, R R R R R R and R, can represent thea same or different organic radicals which have no dyestuf character; Rand R; can represent in addition, hydrogen.

R R R R represent preferably aliphatic radicals such as alkyl andsubstituted alkyl groups, for example methyl, ethyl, n-propyl, n-butyl,hydroxyethyl, B-hydroxypropyl, methoxyethyl, ethoxyethyl groups,however, they may also represent aralkyl'and substituted aralkyl groupssuch as benzyl, methylbenzyl, chlorobenzyl, methoxybenzyl groups orcycloaliphatic radicals such as cyclohexyl, 'methyl-cyclohexyl groups. Rand R can be hydrogen or the same as R in addition R, can also be aheterocyclic radical, for example the Z-pyridyl radical or a'divalentradical linking two. pyrazine radicals, for

example an alkylene or a diphenyl alkane radical;

it can also represent a carbamyl radical, for example the phenylcarbamyl radical and thus X can also represent a urea radical or aureido radical which may possibly be organically substituted. R and Rtogether With the carbarnide-N- atom can also represent a heterocyclicradical, for example a piperidino or a morpholino group.

Because of their fluorescence in ultraviolet light and in daylight, the2.5-di-(sec. amino)-pyrazine-2.6-dicarboxylic acid derivatives of theFormula IV wherein X represents an amine radical, in particular theradical of a primary amine, are suitable for improving the appearance ofmore or. less colorless carriers by optically compensating the yellowingthereof by the violet-blue, blue to green-blue fluorescence. For thispurpose, slight amounts thereof, for example amounts of 0.001 to 1% ofthe carrier, are incorporated into the material to be brightened. Bycarriers are meant substances from the class of natural and syntheticpolypeptides such as wool, silk, polyamide fibres, polyurethane fibres;vinyl polymers such as polyvinyl chloride, polyacrylic acid esters,polystyrene, polyethylenes, unsaturated polyesters; cellulose acylatessuch as cellulose acetates to cellulose triacetate; also cellulosenitrates, e.g. in the form of Zapon varnishes. The 2,.5-di-(sec,amino)-pyrazine-2.6-dicarboxy1ic acid 4 derivatives can also be used asadditives to cosmetic preparations, for example in lipstick and creams.They can be incorporated into carbohydrates such as starches, or fatsand waxes as Well as parafiines.

The following examples illustrate the invention. Where not otherwisestated, parts are given as parts by weight. The temperatures are indegrees centigrade; The relationship of parts by Weight to parts byvolume is as that of kilogram to liters.

Example 1 3.S-bis-ethylaminopyrazine 2.6 dicarboxylic acid-bisethylamideof the formula:

C I-h-NH- C O -L V 212 parts of 1.3 diethy1-4-amino-5-nitroso-uracil and183 parts of l.3-diethyl-4-amino-uracil are dissolved in 7 50 parts ofglacial acetic acid and the solution is refluxed for 3 hours Whilestirring. The grey-greenish solution is cooled, the precipitate formedis filtered off under suction, washed well with water and dried. 320parts of 3.2;5.6-bis[(1'.3'-diethyl-2T.4-dioxo-1.2'.3.4'-tetrahydro)-1.4-pyrimidino]-pyrazine are obtained as white crystalswhich melt at 233.5-234.5. This corresponds to a yield of 89% of thetheoretical calculated on the 1.3-diethyl-4-amino 5-nitrosouracil used.An analytically pure preparationrecrystallized from acetic acid whichmelts at 235.5-236 has the following elementary analysis:

Calculated for C H O N C=53.32%; H=5.59% N=23.32%. Found: C=53.l7%;H=5.61%; N =23.11%.

To saponify the 3.2;5.6-bis-[(1'.3'-diethy1-2.4'-dioxo-1'.2.3.4-tetrahydro)-1.4-pyrimidino]-pyrazine, 10 parts are refluxed for2 /2 hours with 300 parts by volume of 1 N-caustic soda lye and 200parts of ethanol. The precipitate which crystallizes out on cooling isfiltered'ofi under suction, well Washed and dried.

7.5 parts of 3.S-bis-ethylamino-pyrazine-2.6-dicarboxylicacid-bis-ethylamide (MP. 133-134") are obtained. An analytically purepreparation recrystallized from ethanol, has the same melting point andthe following elementary analysis:

Calculated for C H O N C=54.52%; H==7.84%; N:27.25%. Found: C=54.63%;H=8.00%;

On using the corresponding amountsof 1.3-dipropyl-,

1.3-dibutyland 1.3-dimethyl-4-imino-uracil and of 1.3- dipropyl,1.3-dibutyland 1.3-dimethyl-4-amino-S-nitrosouracil, the following3.2;5.6-bis-[(l.3'-dialkyl-2'.4'-dioxotained in a similar manner:

By saponifyingthese according to paragraph 2 of the example, thecorresponding 3.5-bis-alkylaminopyrazine-2.6- dicarboxylicacid-bis-alkylamides are obtained:

M Elementary analysis, percent Alkyl degrees i i C C H H N N cald foundcald found cal'd found 11-G H1 96-97 59. 31 59.43 i 8.85 8. 91 n-CaHo.89-91 (0 CH3 232-233 47. 6 47. 8 6. 35 6. 04 33.3 33. 5

1 The crystals contain crystal solvent.

All these 3.5 bis alkylaminopyraZine-Z.6-dicarboxylicacid-bis-alkylamides have a strong to very strong violetblue fiuoresencedepending on their composition. Because of this property they can beused as follows for improving the appearance of vinyl polymers:

(a) Polyvinyl chloride.-0.07 partsof3.5-bis-methylaminopyrazine-Z.fi-dicarboxylic acid-bis-rnethylamide areadded to 67 parts of polyvinyl chloride powder, 33 parts of dioctylphthalate, 2 parts of di-n-butoxy tin dilaurate and 0.3 parts of sodiumpenta-octyl tripolyphosphate, the mixture is worked on a set of mixingrollers for 15 minutes at 160 and then drawn out into foils. The foilsso produced have a more white appearance in daylight than those producedwithout a content of dialkylaminopyrazine dicarboxylic acid alkylamido.Opaque, white polyvinyl chloride foils of greatly improved appearanceare obtained if 7 parts of titanium dioxide (Anatas) areadded to theabove mixture.

The 3.5-bis-ethylamino-, 3.5-bis-propylaminoand 3.5-bis-butylaminopyrazine-2.6-dicarboxylic acid bis-ethyl-, or -propylor-butylamides described in the above example can be used in the samemanner with the same success.

(b) Polystyrene.---l00 parts of polystyrene powder are thoroughly mixedwith 0.003 parts of 3 .5 -'bis-methylaminopyrazine-2.6-dicarboxylicacid-bis-methylamide and the mixture is then homogenised on a set ofmixing rollers at 130. The hard plates obtained are broken up andfurther worked up on an injection moulding machine or in presses.Objects having a much more white appearance in daylight than thoseproduced without the addition of2.S-bis-alkylaminopyr-azine-2.G-dicarboxylic acid bis alkamides areobtained.

Opaque objects of improved appearance are obtained if 2 parts oftitanium dioxide (Anatas) are added to the above mixture. The3.5-bis-ethylamino-, 3.5-bis-propylaminoand3.5-bis-butylaminopyrazine-2.G-dicarboxylic acidbis-ethylamides,-bis-pyropylamides, or -bis-butylamides also described in the aboveexample can be used in the same manner and with similar success.

I (c) .Polyethylene.0.05 parts of3.5-bis-propylaminopyrazine-Z.G-dicarboxylic acid bis-propylamide aremixed dry at room temperature with 100 parts of high pressurepolyethylene in granulate form and the mixture is then worked into atube in the extruder at 120l30. The objectis considerably more whitethan that produced without brightening agent.

To produce opaque polyethylene, 0.1 parts of3.5-bispropylaminopyrazine-Z.6-dicarboxylic acid-'bis-propylamide, 2parts of titanium oxide and parts of polyethylene granulateare mixed andpressed at-130".

A material is obtained in this way which has a considerably more whiteappearance in daylight than that produced without brightening agent. The3.5-bis-ethylamino-,

3.5-bismethylaminopyrazine-2.6-dicarboxylic acid-bisethyl or -methylamides described in the above example can be used, in the same mannerand with similar success.

(d) Polymethacrylic acid methylester.0.004 parts of then temperedfor 1hour at Because of its very beautiful blue-violet:fiuorescence, theglass clear resinous body obtained has amore brilliant appearance indaylight than a non brightened material.

If the brightening agent used is replaced by the same amount of the3.5-bis-ethylaminoor 3.5-bis-proplyaminopyrazine-2.6-dicarhoxylicacid-bis-ethylor -propylamides described in the above example, thensimilar beautifully brightened products are obtained. i (e) Acetylcellulose-0.2 parts of 3.5-=bis-ethylaminopyrazine-2.6-dicarboxylicacid-bis-ethylamide, 25 parts of diethyl phthalate and 75 parts ofacetyl cellulose are dis solved in 900 parts of acetone. The solution ispoured onto glass plates and, after evaporation of the acetone, atransparent film is obtained. In daylight this film appears much morebrilliant than a corresponding film produced without the addition ofbrightening agent.

Opaque cellulose acetate films are obtained if. 5 parts of titaniumdioxide (Anatas) are added to the above mixture before it is pouredontothe glass plates The opaque films obtained are much more whiteindaylight than comparative samples produced without brightening agents.

The '3.5-bis-methylamino-, 3.5-bis-propy1amino and3.5-bis-butylaminopyrazine-2.6-dicarboxylic acid-bismethylor -propyl or-butyl amides described in the above example can be used in the samemanner with the same success.

if, in the first paragraph under (e) of this example, the diethylphthalate is not added, then a solution in acetone is obtained whichproduces cellulose fibres of greatly improved appearance in the dryspinning process.

The appearance of cosmetics can also be improved with the3.S-bis-alkylaminopyrazine2.6-dicarboxylic acid-bisalkylamides asfollows:

(f) Creams-A cold cream of dazzling white appearance is obtained if 0.1parts of 3.5-bis-methylaminopyrazine-2.6-dicarboxylicacid-bis-methylamide are dissolved in 25 parts of cetyl alcohol and thissolution is mixed homogenously in the mixing apparatus with 55 parts ofparaflin oil, 10 parts of bleached beeswax and 10 parts of wool fat(anhydrous).

Similar creams are obtained if, instead of the brightening agentmentioned, the 3.5-bis-ethylaminoor3.5-bispropylamino-pyrazine-2.6-dicarboxylic acidbis-ethyl or -propylamides mentioned in the above example are used.

Because of their favorable shade of fluorescence and their afiinity,these 3.S-bis-alkylaminopyrazine-2.6-dicarboxylic acid-bis-alkylamidesare also suitable for the optical brightening of natural and syntheticpolypeptide fibres according to the application methods described inExamples 2 and 3.

Example 2 3-propylamino-5-ethylamino-pyrazine-2-carboxylie acidpropylamide-6-carboxylic acid ethylamide of the formula:

cooled and diluted with water. The precipitate formed is filtered offunder suction, washed well with water and dried. 70 parts of 3.2-[(l'.3'diethyl 2'.4' dioxo- 1'.2'.3.4-tetrahydro)-1'.4'-pyrimidino] 5.6-l'.3'-dipro .pyl-2'.4-dioxo-1'.2.3.4'-tetrahydro)-l'.4' pyrimidino]pyrazine are obtained in the form of white crystals which melt at147.5-149". This corresponds to a yield of 90% of the theoretical,calculated on the 1.3-diethyl-4-arnino-5- ntroso-uracil used. Ananalytically pure product recrystallised from ethanol melts at 150-151"and has the following elementary analysis:

' Calculated for C d-1 N 0 2 Found .C=55.70%; H=6.52%.

parts are refluxed for 2% hours with 300 parts by volume of 1 N-causticsoda lye and 200 parts of ethanol. The reaction mixture is cooled andthen neutralised with diluted hydrochloric acid. The precipitate formedis filtered ofi under suction, Washed and dried. 7.2 parts 0153- 25propylamino-5-ethylamino-pyraZine-2.6-dicarboxylic acid- '2propylamide-6-ethylamide are obtained. M.P. 91 923 An analytically purepreparation recrystallised from ethanol has the following elementaryanalysis:

Calculated for C H N O C=57.12%; H=8.39%; 30

On condensing 4-amino-uracils with 4-amino5-nitroso-' Found C=57.l4%;H=8.45%;

uracils which are differently alkyl substituted at the ring nitrogenatom, for example by using corresponding amounts of l.3-dimethyl-,1.3-diethyland 1.3-dipropyl- 4-amino-uracils and l.3-dimethyl-,1.3-diethy1- and 1.3-

'1 and 6.005 part of 3-propylamino-5methylaminopyrazine-Z-car'ooxylicacid-propylaniide--carboxylic' acid methylamide. The fabric is thenrinsed and dried in the air. The fibres so treated have a much moreWhite appearancein daylight than untreated goods. 1

The 3 -methylamino-5-ethylamino-pyraZine-2-carboxylicacid-methylamino-6-carboxylic acid ethylamide and 3-- propylaminoS-ethylamino-2-carboxylic acid-propylamide-6-carboxylic acid ethylamidedescribed in the above example can be used in the same way with similarsuccess.

flannel are washed for half anhour at in 2000 parts of a washing liquorcontaining 5 parts of an alkylaryl sulphonate of the marketed nameSantomerse No. 1 and 005 parts of 3-propylamino-5-ethylaminopyrazine-2-carboxylic acid-propylamide-6-carboxylic acid-ethylamide.

The Wool is then rinsed and dried in the air. 'In this way" wool of aconsiderably more white appearance is obtained than when the wool iswashed without the addition of the brightening agent. 7

The 3-propylamino-5-methylamino-pyrazine-2-carboxylicacid-propylamide-6-carboxylic acid methylamide and 3methylamino-5-ethylaminopyrazine-Z-carboXylic acidmethylamide-G-carboxylic acid ethylamide described in.

dipropyl 4-amino-S-nitroso-uracils, the following unsymmetrical 3.2;5.6-[1'.3'-dialkyl-2.4'-dioxo-112C314 7 tetra CHPNH-Chydro)-l'.4'-pyrimidino]-pyrzaines are obtained in the 49 CH3-NH-'fi-CCGNH I I same way. N l

. Elementary analysis, percent Lalkyl 2.alkyl M.P.. R18! R2 R3 & R;degrees C cald 0 found H eald H found N cald N found CH3 n-C H 169-163.5 53.32 53.36 5.59 5. 57 23.32 23.24 CH O2H 253254 50.60 50. 01 4.854.72

On saponifying these according to paragraph 2 of the above example, thecorresponding unsymmetrical l.3-bisalkylamino-pyrazine-2.6-dicarboxylicacid-bis-alkylamides are obtained:

31 parts of 1.3-dimethyl-4-amino-uracil and 40 parts of1.3-dimethy1-4-amino-5-nitroso-uracil are refluxed while stirring for 3hours in 200 parts of glacial acetic acid. The reaction mixture iscooled, the precipitate formed is Elementary analysis, percent Lalkyl2.alkyl M.P., R & R7 R & R degrees C eald 0 found H cald 11 found N ealdN found OH n-G H 136-137 54. 52 54. 64 7. 84 8. 02 27. 25 26. 98 CH CZH169-170 51. 41 51. 66 7. 19 7. 17 29. 98 29. 95

7 All these unsymmetrical 3.5-bis-alkylamino-pyrazine- 2.6-dicarboxylicacid-bis-alkylamides have. a strong to very strong violet-bluefluorescence depending on their composition; Due to this property, theycan be used for the brightening ofnatural and synthetic polypeptides as70 follows:

(a) Synthetic p0lypeptides.-50 parts of pale yellowish Nylon fabric arewashed for 30 minutes at 70 in 2500 parts of a washing liquor containing6.3 parts of an alkylaryl sulphona-te of the marketed name SantomerseNo. 7

filtered oil? under suction, washed Well with water and dried. 51 partsof 3.2;5.6-bis-[(1'.3'-dimethyl-2'.4'-dioxo- 1' .2 .3.4-tetrahydro 1.4'-pyrimidino] -pyrazine are obtained in the form of white crystalswhich melt at 390 (the melting point depends on the heating time). Thiscorresponds to a yield of 84% of the theoretical, ca1culated on the1.3-dimethyl-4-amino-uracil used. Recrystallised from acetic acid, ananalytically pure preparation has the following elementary analysis: 7

Calculated for C H O N C=47.4%; H=4.l7%;

(b) WOOL- parts of previously bleached wool N=27.8%. Found: O=47.4%;H=3.95%; N;27.6%.

To saponify the 3.2;5.6-bis-[(1'.3-dimethyl-2'.4-dioxo- 1'.2.3'.4tetrahydro) 1'.4'-pyrimidino]-pyrazine, 152 parts are refluxed for 6hours with a solution consisting pants of aniline and 400 parts of abs.pyridine, which i solution is cooled with a mixture of ice/ sodiumchloride See footnote at end of table.

of 200 parts of potassium hydroxideand 2400 parts of 5 and washed wellwith water. Pale yellow crystals of ethanol. 117 parts of 3.5bis-methylamino-2-carboxy- 3.S-bis-rnethylamino-pyrazine-Z-carboxylicacid phenyl-; pyrazine-S-carboxylic acid methylamide (M.P. 214,deamide-6-carboxylic acid methylamide are obtained which compositiondependent on the heating time) are obtained. melt at 195-197Recrystallised from ethanol, an analytically pure prepa- Recrystallisedfrom ethanol, an analytically pure prepration has the followingelementary analysis: 10 aration melts at 198-1985 and has the followingele- Calculated for C H O N /2H O: C=43.48%; mentary analysis:H=5.68%;N-=28.3%. Found: C=43.59%;H==5.50% Calculated for C H O NC=57.31%; N=5.77%; N=28.45%. N=26.74%. Found C=57.42%; N=6.01%; N=

To amidate the 3.S-bis-methylarnino-2-carboxypyraz- 26.86%.ine-G-carboxylic acid methylamide 20 parts are mixed 15 Amidafion 0f yY-PY with 150 parts of thionyl chloride. The mixture is left to y acid yfimide in pyridine or in an aquestand for minutes and then the excessthionyl chloride ous medium according to paragraph 3 of this example isremoved in the vacuum. The remaining crystalline with the aminescorrespo d ng to R in the following acid chloride is then slowly addedto a solution of 10 table, pr the following Compclmds! CH NHC \C-NHCH3CH NH-(J -C-R No. R M.P.,1 Colour of degrees fluorescence 1 NH2 290-292Violet-blue.

2 -NHOHCH2OH 21o-21o.5 Do.

a NHGHCHz-CH: 218-219 Do.

4 NH-CH -OH3 197-19215 Lo.

5 NHCH2O 218.5-220 Blue-violet.

e -NHOHz-CH:-O 76-78 Do.

7 -NH 126.5427 Blue.

(SCH:

s '-NH-OHIOHzOH2-CH3 194 196 Violet-blue.

9 NHOOC: 252-254 Blue.

10 Nl1-CHz-OH=CH2 1944955 Violet-blue.

11 -NH-'(CHfl)7 CH3 121-121; Do.

CH2-CH2 12. -NH0 9H2 237-238.. Blue-violet.

CH3 13-.." N 128-129 VlOlGl].

CHa

CHz-CH 14 NH-O 188-190 Violet-blue.

HCCH

15 -NH-C 0-H 223-224 Blue-violet.

N==OH i 16 NH-(Il-CHa 204-205 Violet-blue;

17 NH-C "CHa 211- 2125 Blue-violet.

18... NH- 194-195 Do.

1 No. R M.P., Colour of degrees fluorescence 232-234 Do. 36"-.- -HN 1The melting points depend greatly on the heating time.

1 The melting points depend greatly on the heating time. 1

On using corresponding amines of 1.3-dibenzyland 1.3-diethyl-4amino-uracils and 1.3-dibenzyland 1.3-diethyl-4-amino-5-nitro-uracils,the 3.2;5.6-bis-[(1.3'-dibenzyl 2'.4' dioxo 1'.2'.3'.4'tetrahydro)-l'.4.- pyrimidino]-pyrazines and 3.2;5.6-bis[(l'.3'-diethyl-2'.4'-dioxo-l.2'.3.4-tetrahydro) l'.4'-pyrin1idino]-pyrazines areobtained in the same manner. On saponifying these according to paragraph2 of this example, the corresponding 3.5-bissubstitutedaminopyrazine-2-carboxylic acid-6-carboxylic acid benzylor ethylamidesare 3.5 bis methylamino pyrazine 2 carboxylic acidphenylamide-6-carboxylic acid methylamide and 0.2 parts of formic acid.After rinsing and drying, the fabric treated has a much more whiteappeaarnce in daylight than before treatment. 1 1

(2) 50 parts of undyed Nylon are Washed at 70 for half an hour inawashing liquor (liquor ratio 1:20) containing 0103 parts of3.5-bis-methylaminopyrazine-Z-carboxylicacid-[3-methoxyphenylamide]-6-carboxylic acid methylarnide and 8 partsof dodecyl benzene sulphonate,

and then rinsed and dried. The Nylon so treated has a much morebrilliant appearance in daylight than material washed without theaddition of brightening agent. In-

. stead of dodecyl benzene sulphonate, also other synthetic washing andcleansing agents such as, for example, fatty alcohol sulphates or oleoyltauric acid. alkali salts etc. can be used.

The following compounds described in the above tables can be used in thesame manner with similar success instead of the brighteningagentsmentioned: Nos. 1, 2, 3, 4, 5, 6, 8, 10, 11, 12, 14, 15, 16, 19, 20, 21,22, 23, 24, 25, 26, 27, 29, 30, 31, 33, 34, 36, 38, 39, and 41.

(b) W00l.-(1) 25 parts of white woolen knitted goods are treated in adyebath (liquor ratio 1:30) for half an hour at 50-55 which contains0.02 parts of 3.5- bis-methylaminopyrazine-Z-carboxylic acidphenylamide- 6-carboxylic acid methylamide and 0.5 parts of formic acid.The goods are then rinsed and dried. The wool 1 so treated is clearlymore White in daylight than untreated obtained. 40 wool.

Elementary analysis in percent Substituent M.P., R R and R degrees 1 Ccald 0 found H cald H found N cald N found -CH7 161-162 69.36 69. 305.39 5.36 14.98 15.06 C1Hs 174-175 51. 23 51.32 6.81 7. 02 24. 90 25.08

By amidation in pyridine according to paragraph 3 of (2) parts ofpreviously bleached wool flannel are this example, the corresponding3,5-bis-ethyl-or -benzyl treated for 1 hour at 5055 in a dyebath (liquorratio aminopyrazine-2-carboxy1ic acid ethylor benzylamide- 1:20)containing 3 parts of sodium hydrosulphite and 1 G-carboxylic acidamides are obtained, for example: part of sodium pyrophosphate and also0. 05 parts of 3.5-

Substitu- Elementary analysis in percent No. ent R1,Rz X M.P.,

and Rs degrees C eald 0 found H cald H found N cald N found 40..w 02H5NH@ 14115-1415 60.65 60.77 6.79 7.07 23.58 23.55

41... (Jim -NHC 108-109 56.9 56.6 6.7 6.7 26.6 26.6

1 E HG CH (a) Synthetic p0lypeptides.(1) 10 parts of a paleyellowishNylon fabric are treated for 30 minutes at inadyebath (liquor ratio1:40)coi1taining 0.01'parts of used inthe'same'rnanner with the samesuccess: Nos. 1,2,

bis-methylaminO-pyraZine-Z-carboxylic acid phenylamide- 70 6-carboxylicacid methylarnide. After rinsing and drying,

The following compounds in the above tables can be 3, 4, 5, 6, 7, 8, 10,11, 12, 14, 15, 16, 18, 19, 21, 22 23, 24,25, 27, 29, 30, 31, 39, 40 and41.

i Pure silk.10 parts of pale yellowish pure silk are washed at 55 for 30minutes in 200 parts of a washing The compound melts at 160162' (thRecrystallised from methanol, an analytically pure [preparation has thefollowing elementary analysis:

liquor containing 0.5 parts of an alkylaryl sulphonate of Calculated forC H 0 N 'C 49.43%; H=6.41%; the marketed name Santome'rse No. 1 and 0.01parts N=26.20%. Found: C=49.99%; H=6.49%; N: of 3.5-bismethylamino-pyrazine-Z-carboxylic acid phen- 26.27%. aylamide-r6-carboxylic acid methylamide, and then rinsed To amidate the3-methylamino-3-ethylamino-pyr i and dried in the air. In this way, puresilk of consid- Z-carboxylic acid-6-carboxylic acid ethylamide, 20 partserably more'white apparance is obtained than if it had 10 of thiscompound are mixed with 100 parts of thionyl been washed without theaddition of the brighten ng chloride. Themixture is left to stand for 45minutes agent named. and then excess thi-onyl chloride is removed in theAlso very beautiful effects are obtained if instead of vacuum. The acidchloride which remains is then poured the br ghten ng ag nt us d a t f lg into a solution of 300 parts of concentrated aqueouspounds mentionedin the tables are used NOS- 1, 2, ammonia and 100 parts of ethanol,which solution has 4, 5, 7, 11, 12, 15, 27 and 31. been cooled with amixture of ice and sodium chloride. Acetate P s Of ac t Silk fabric aThe whole is stirred overnight. The precipitate formed treated at 7 for30 minutes in a bath q ratio is filtered off under suctionand washedWell with water. 1:30) containing 0.0025 parts of 3.5-bis-methylamino- 3methylamino-5-ethylamino-pyraZine-2-carb0Xylic acidpyrazine-Z-carboxylic acid phenylamide-6-carboxylic acidamide-6-carboxylic acid ethylamide is obtained in the methylamide- Afterrinsing and drying, the fabric has v form of pale yellow crystals whichmelt at 212-'214. a considerably more white appearance than beforetreat- Recrystallised from ethanol, an analytically pure prepment.aration melting at 223234 has the following elementary The followingcompounds described in the above analysis:

tables can be used in the same manner with similar suc- Calculated for CH O N C==49.6l%; H=6.81%; cess instead of the brightening agentmentioned: Nos. N=31.56%. Found: C=49.49%; H=6.90%; N= 1, 2, 3, 4, 5,6,7, 8, 10, 11, 12, 14, 15, 16, 18, 19, 20, 31.88%. 21, 22, 23, 26, 27,29, 31, 33, 35, 39, 40 and 41. The following3-methylamino-5-ethylamino-pyrazine- (e) Cellulose triacetate.-10 partsof cellulose tri- Z-carboxylic acid alkylamide-6-carboxylic acidethylacetate silk fabric are treatedfor half an hour in a dye- 30 amidesfor example are obtained in the same manner bath on a boiling waterbath, the dyebath liquor ratio on amidation with other amines:

Alkyl My lementary analysis in percent degrees C cald 0 found H cald Hfound N cald N found --CzHs 162-164 53.04 53.06 7. 53 7.59 28.55 28.53

-oan7 84-86 53. 3 53. 4 7. 85 7. 9s 26. 7 20. s

being 1:30 and containing 0.005 parts of 3.5-bis-methyl- Depending ontheir composition, all these 3-methylaminopyrazine 2 carboxylic acidphenylamide-6-caramino-5-ethylamino-2-carboxylic acidalkylamide-6-carboxylic acid methylamide. After rinsing and drying, theboxylic acid ethylamides have a strong to very strong fabric has a muchmore brilliant appearance than before violet-blue fiuoroescence. Becauseof this property they treatment. canbe used for the brightening ofnatural as well as syn- Instead of3.5-bis-methylamino-pyrazine-Z-carboxylic thetic polypeptide fibres.acid phenylamide-6-carboxylic acid mcthylamide, the fol- Wool treated inan acid bath according to paragraph lowing compounds described in theabove tables can be (b) of Example 3 or in a neutral bath according toparaused in the same way with similar success: Nos. 1, 2, 3, graph (b)of Example 2 has a considerably more White 4, 5, 7, 11, 12, 15, 27 and31. appearance than untreated wool.

The compounds described in the above Example 3 are Nylon treated in anacid bath according to. paragraph also very well suited for thebrightening of synthetic (a) of Example 3 has a much more white andluminous materials and cosmetics, the procedure being as describedappearance than before treatment. in Examples 1 and 2. Also fibres madeup from cellulose acylates can be Example 4 beautifully brightened withthese unsymmetrical pyrazine 3 farts; reassessment stains? acidannde-6-carboxyl1c acid ethylannde of the formula. graph (d) of Example3 than untreated fabric.

Such 3 methylamino 5 ethylamino 2 carboxylic O,H -NHO C-NH-CH acidalkylamide-6carboxylic acid methyl amides are also C2H5 NH G suitablehowever for the brightening of vinyl polymers I] because of theirintensive fluorescence. Thus for ex- O N O ample, polyvinyl chloridefoils produced according to T0 p y the Y paragraph (a) of Example 1,have a much more white tetrahydfo) '-PY appearance in daylight than suchfoils which contain no ethyl 2'.4' dioxo1'.2'.3.4'-tetrahydro)-1'.4'pyrimib i h i agent dinol-pyrazine, producedfor example as in Example 2, Example 5 57 parts'of this compound arerefluxed for 6 hours with a solution consisting of 45 parts of potassiumhydroxide 0.075 parts of 3.5 bis methylamino pyrazine 2- and 500 partsof ethanol. The ethanol is distilled off, carboxylicacid-phenylamide-G-carboxylic acid methylthe reaction mixture isacidified with diluted hydrochloric amide are worked into 100 parts ofsoap powder consistacid and 43 parts of 3-methylamino-S-ethylaminoing ofthe sodium salt of fatty acids with 5% water conpyrazine-Z-carboxylicacid-G-carboxylic acid ethylamide tent. Nylon fabric washed at 40 in awashing liquor 17 (liquor ratio 1:30) containing parts per litre of thesoap powder described above, has a much more brilliant appearance.

If, in the above washing agent, 0.09 part of 3.5-bismethylamino-pyrazine2.6 dicarboxylic acid methylamide are used instead of the pyraiznenamed, then the treated fibres also have a beautiful white appearance.If an even stronger brightening effect on acetate silk is required, then1 to 2 parts of the brightening agent named can be used.

Example 6 0.075 part of 3.S-bis-methylamino-pyrazine 2 carboxylic acidphenylamide-6-carboxylic acid methylamide are worked into 100 parts ofwashing agent consisting of 55% sodium salt of lauryl alcohol sulphate,40% sodium sulphate, 2% carboxymethyl cellulose and 3% water content.

Wool, as well as nylon and acetate silk fabric, which is washed at 40-50in a washing liquor (liquor ratio 1:30) containing 5 parts per litre ofthe washing agent described above, has a beautiful white appearance.

If, instead of the pyrazine in the above anion active washing agent, 0.2parts of 3.5-bis-methylamino-pyrazine- 2.6-dicarboxylic acid methylamideor 0.2 part of 3-propylamino-S-niethylamino-pyrazine-2-carboxylic acidpropylamide-6-carboxylic acid methylamide or 0.15 parts of 3- ethylamino5 methylamino pyrazine 2.6 dicarb oxylic acid ethylamide or 0.3 part of3-propylmino-5- ethylamino-pyrazine 2 carboxylic acid propylamide-6-carboxylic acid ethylamide or 0.2 parts of 3-ethylamino-5methylamino-pyrazine 2 carboxylic acid ethylamide- 6-carboxylic acidbenzylamide are used, then similar effects are obtained on treating thefibres above mentioned.

Instead of the anion active washing agent described, also thoseconsisting of salts of sulphonic acid esters of ethoxylated fattyalcohols or salts of sulphonic acid esters of alkanol amides of fattyacids can be used.

Example 7 0.05 parts of 3.5 bis methylamino pyrazine 2- carboxylic acidphenylamide-G-carboxylic acid methylamide are worked into 100 parts ofwashing agent of the composition: 20% dodecyl benzene sulphonate, sodiumlauryl s'ulphonate, 2% carboxymethyl cellulose sodium lauryl sulphonate,2% carboxymethyl cellulose, 15 tetrapyrophosphate, tripolyphosphate, 22%sodium sulphate and 6% water.

If nylon or acetate silk is washed at 60 in a washing liquor containing6 parts per litre of the washing agent described, then the fabric has abrilliant appearance.

If, in the above washing agent instead of the pyrazine mentioned, 0.12parts of 3.5 bis ethylamino pyrazine- 2.6 dicarboxylic acid methylamideare used, then the fibres mentioned also have a beautiful appearance.

If the washing agent contains 0.15 parts of 3.5-bismethylamino pyrazine2 carboxylic acid pyridylamide- 6-carboxylic acid methyl amide, thenwool flannel or acetate silk washed therein has a beautiful whiteappearance.

Example 8 0.2 parts of 3.5 bis methylamino pyrazine 2.6- dicarboxylicacid methylamide are incorporated into 100 parts of washing agentconsisting of 45% soap, 5% water glass, 10% pyrophosphate, 15% sodiumcarbonate, 3% magnesium meta silicate, 7% perborate and 15% water.

Nylon and acetate silk fabric which are washed at 70 in a washing liquor(liquor ratio 1:30) containing 8 parts per litre of the above washingagent have a much more white appearance than when washed without theadidtion of the brightening agent.

If in the above washing agent, instead of the brightening agent named,0.06 parts of 3.5-bis-methylamino-pyrazine- 2-carboxylic acidpyridylamide-G-carboxylic acid methylamide or 0.04 parts of3.5-bis-methylamino-pyrazine-2- carboxylic acid phenylamide-6-carboxylicacid methylamide, are used, then similar effects on the above mentionedfibres are obtained.

Example 9 0.1 parts of 3.5-bis-ethylamino-pyrazine-2.6-dicarbox ylicacid ethylamide are incorporated into parts of washing agent of thecomposition: 12% dodecyl benzene sulphonate, 10% sodium lauryl sulphate,5% water glass, 2% carboxymethyl cellulose, 15 tripolyphosphate, 20%pyrophosphate, 10% sodium carbonate, 20% sodium sulphate and 6% water.

Nylon fabric which is washed at 70 in a Washing liquor (liquor ratio1:30) containing 8 parts per litre of the washing agent described above,has a brilliant appearance.

If, in the above washing agent, instead of the pyrazine mentioned, 0.08parts of 3.5-bis-methylarnino-pyrazine- 2.6-dicarboxylic acidmethylamide or 0.005 parts of 3.5- bis-methylamino-pyrazine-2-carboxylicacid phenylarnide- 6-carboxylic acid methylamide are used, then abrightening effect is also obtained.

Example 10 0.1 parts of 3.S-bis-methylamino-pyrazine-Z-carboxylic acidphenylamide-6-carboxylic acid methylamide are added to 100 parts ofwashing agent consisting of 30% of a condensation product of oleic acidand methyl taurine, 65% sodium sulphate and 5% water.

Nylon fabric Washed at 50 in a washing liquor containing 5 parts perlitre of the washing agent described has a much more white appearancethan fabric washed without the addition of brightening agent.

. Acetate silk fabric washed under the same conditions with a washingagent of the same composition but containing 0.15 parts of3.5-bis-ethylamino-pyraZine-2.6-dicarboxylic acid ethylamide instead ofthe pyrazine named, also has a beautiful white appearance.

Also a Washing agent consisting of the condensation product of oleicacid and taurine can be used instead of that described. t

Example 11 0.075 parts of 3-ethylamino-S-methylarnino-pyrazine-2.6-dicar.boxylic acid ethylamide are incorporated into 100 parts ofwashing agent consisting of 25% of a sulphonated condensation product ofp-methoxyphenyl diguanide and oleic acid (1-p-methoXyphenyl-2imino-4-amino-6oleyl-1.3.5-triazine sulphonic acid), 70% sodium sulphate and 5%water.

Nylon fabric washed at 50 in a washing liquor (liquor ratio 1:30) whichcontains 5 parts per litre of the Washing agent described above, has abrilliant appearance.

Wool fabric washed under the same conditions with the above washingagent but containing 0.15 parts of3.5-bisethylamino-pyrazine-2.6-dicarboxylic acid ethylamide instead ofthe pyrazine named, also has a very beautiful White appearance.

A beautiful brightening effect on acetate silk is obtained if, in thewashing agent described above, 0.075 parts of3.S-bis-methylamino-pyrazine-2-carboxylic acid phenylamide-6-carboxylicacid ethylamide are used instead of the pyrazine mentioned.

The present application is a division of co-pending application, Ser.No. 737,215, filed May 23, 1958.

What we claim is:

1. A composition of matter of improved appearance in daylight consistingessentially of an uncoloured carrier selected from the group consistingof synthetic polypeptides, natural poly-peptides, vinyl polymers andcellulose acetates, containing from 0.001 to 0.5% by weight, of the 1composition, of a 3.S-diamino-pyraZine-Z.G-dicarboxylic acid amide ofthe formula:

wherein R R and R each is a member selected from the group consisting oflower alkyl and phenyl substituted methyl radicals and X is a memberselected from the group consisting of primary amino, secondary amino,tertiary amino and ureido groups.

2. A composition of matter of improved appearance in daylight consistingof wool and from 0.001 to 0.5% by Weight, of the composition, of a3.5-diamino-pyrazine-2.6- dicarboxylic acid amide of the formula:

wherein R R and R each is a member selected from the group consisting oflower alkyl and phenyl substituted methyl radicals and X is a memberselected from the group consisting of primary amino, secondary amino,tertiary amino and ureido groups.

3. A composition of matter of improved appearance in daylight consistingof nylon and from 0.001 to 0.5 by weight, of the composition, of a3.5-diamino-pyraZine-2,6- dicarboxylic acid amide of the formula:

wherein R R and R each is a member selected from I the group consistingof lower alkyl and phenyl substituted methyl radicals and X is a memberselected from the group consisting of primary amino, secondary amino,tertiary amino and ureido groups.

4. A composition of matter of improved appearance in daylight consistingof cellulose acetate and from 0.001 to 0.5% by weight, of thecomposition, of a 3.5-diaminopyrazine-Z.6-dicarboxylic acid amide of theformula:

wherein R R and R each is a member selected from the group consisting oflower alkyl and phenyl substituted methyl radicals and X is a memberselected from the group consisting of primary amino, secondary amino,tertiary amino and ureido groups.

6. A composition of matter of improved appearance in daylight consistingof polystyrene and from 0.001 to 0.5 by weight, of the composition, of a3.5-diamino-pyrazine- 2.6-dicarb0xylic acid amide of the formula:

wherein R R and R each is a member selected from the group consisting oflower alkyl and phenyl substituted methyl radicals and X is a memberselected from the group consisting of primary amino, secondary amino,tertiary amino and ureido groups.

7. A composition of matter of improved appearance in daylight consistingof polyethylene and from 0.001 to 0.5% by weight, of the composition, ofa 3.5-diaminopyrazine-Z.6-dicarboxylic acid amide of the formula:

wherein R R and R each is a member selected from the group consisting oflower alkyl and phenyl substituted methyl radicals and X is a memberselected from the group consisting of primary amino, secondary amino,tertiary amino and ureido groups.

References Cited in the file of this patent UNITED STATES PATENTS2,581,889 Timmis Jan. 8, 1952 2,972,611 Zweidler et al Feb. 21, 19613,063,994 Adams et al Nov. 13, 1962 OTHER REFERENCES Raybin: ChemicalAbstracts, vol. 39 (1945) 44333.

Taylor: Chemical Abstracts, vol. 49 (1955) 6966 and 6967

1. A COMPOSITION OF MATTER OF IMPROVAL APPEARANCE IN DAYLIGHT CONSISTINGESSENTIALLY OF AN UNCOLOURED CARRIER SELECTED FROM THE GROUP CONSISTINGOF SYNTHETIC POLYPEPTIDES, NATURAL POLYPEPTIDES, VINYL POLYMERS ANDCELLULOSE ACETATES, CONTAINING FROM 0.001 TO 0.5% BY WEIGHT, OF THECOMPOSITION, OF A 3.5-DIAMINO-PYRAZINE 2.6-DICARBOXYLIC ACID AMIDE OFTHE FORMULA: